From 0a5e06d62cda2348d11f885ec282830c9a2d4159 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Sat, 18 Oct 2014 13:58:01 -0700
Subject: [PATCH] terraform: merge interpolated inherited provider
 configurations [GH-418]

---
 CHANGELOG.md                                  |  1 +
 terraform/context.go                          | 12 ++++-
 terraform/context_test.go                     | 49 +++++++++++++++++++
 terraform/graph.go                            |  2 +-
 .../child/main.tf                             |  8 +++
 .../plan-module-provider-defaults-var/main.tf |  7 +++
 6 files changed, 76 insertions(+), 3 deletions(-)
 create mode 100644 terraform/test-fixtures/plan-module-provider-defaults-var/child/main.tf
 create mode 100644 terraform/test-fixtures/plan-module-provider-defaults-var/main.tf

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d6785e32b598..b20b9b9f7152 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,7 @@ BUG FIXES:
   * core: Set types are validated to be sets. [GH-413]
   * core: Fix crash case when destroying with tainted resources. [GH-412]
   * core: Don't execute provisioners in some cases on destroy.
+  * core: Inherited provider configurations will be properly interpolated. [GH-418]
   * providers/aws: Refresh of launch configs and autoscale groups load
       the correct data and don't incorrectly recreate themselves. [GH-425]
   * providers/aws: Fix case where ELB would incorrectly plan to modify
diff --git a/terraform/context.go b/terraform/context.go
index 6fa7938734cc..c6f367fb5eb7 100644
--- a/terraform/context.go
+++ b/terraform/context.go
@@ -1203,9 +1203,17 @@ func (c *walkContext) genericWalkFn(cb genericWalkFunc) depgraph.WalkFunc {
 			}
 
 			for k, p := range sharedProvider.Providers {
-				// Merge the configurations to get what we use to configure with
+				// Interpolate our own configuration before merging
+				if sharedProvider.Config != nil {
+					rc := NewResourceConfig(sharedProvider.Config.RawConfig)
+					rc.interpolate(c, nil)
+				}
+
+				// Merge the configurations to get what we use to configure
+				// with. We don't need to interpolate this because the
+				// lines above verify that all parents are interpolated
+				// properly.
 				rc := sharedProvider.MergeConfig(false, cs[k])
-				rc.interpolate(c, nil)
 
 				log.Printf("[INFO] Configuring provider: %s", k)
 				err := p.Configure(rc)
diff --git a/terraform/context_test.go b/terraform/context_test.go
index 16f1be98bf19..f3b8cd6efb99 100644
--- a/terraform/context_test.go
+++ b/terraform/context_test.go
@@ -1,6 +1,7 @@
 package terraform
 
 import (
+	"bytes"
 	"fmt"
 	"os"
 	"reflect"
@@ -2903,6 +2904,54 @@ func TestContextPlan_moduleProviderDefaults(t *testing.T) {
 	}
 }
 
+func TestContextPlan_moduleProviderDefaultsVar(t *testing.T) {
+	var l sync.Mutex
+	var calls []string
+
+	m := testModule(t, "plan-module-provider-defaults-var")
+	ctx := testContext(t, &ContextOpts{
+		Module: m,
+		Providers: map[string]ResourceProviderFactory{
+			"aws": func() (ResourceProvider, error) {
+				l.Lock()
+				defer l.Unlock()
+
+				p := testProvider("aws")
+				p.ConfigureFn = func(c *ResourceConfig) error {
+					var buf bytes.Buffer
+					if v, ok := c.Get("from"); ok {
+						buf.WriteString(v.(string) + "\n")
+					}
+					if v, ok := c.Get("to"); ok {
+						buf.WriteString(v.(string) + "\n")
+					}
+
+					calls = append(calls, buf.String())
+					return nil
+				}
+				p.DiffFn = testDiffFn
+				return p, nil
+			},
+		},
+		Variables: map[string]string{
+			"foo": "root",
+		},
+	})
+
+	_, err := ctx.Plan(nil)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	expected := []string{
+		"root\n",
+		"root\nchild\n",
+	}
+	if !reflect.DeepEqual(calls, expected) {
+		t.Fatalf("BAD: %#v", calls)
+	}
+}
+
 func TestContextPlan_moduleVar(t *testing.T) {
 	m := testModule(t, "plan-module-var")
 	p := testProvider("aws")
diff --git a/terraform/graph.go b/terraform/graph.go
index f79189195cfd..b52dacdd1f69 100644
--- a/terraform/graph.go
+++ b/terraform/graph.go
@@ -1597,7 +1597,7 @@ func (p *graphSharedProvider) MergeConfig(
 	if override != nil {
 		rawMap = override
 	} else if p.Config != nil {
-		rawMap = p.Config.RawConfig.Raw
+		rawMap = p.Config.RawConfig.Config()
 	}
 	if rawMap == nil {
 		rawMap = make(map[string]interface{})
diff --git a/terraform/test-fixtures/plan-module-provider-defaults-var/child/main.tf b/terraform/test-fixtures/plan-module-provider-defaults-var/child/main.tf
new file mode 100644
index 000000000000..5ce4f55fe841
--- /dev/null
+++ b/terraform/test-fixtures/plan-module-provider-defaults-var/child/main.tf
@@ -0,0 +1,8 @@
+provider "aws" {
+    from = "child"
+    to = "child"
+}
+
+resource "aws_instance" "foo" {
+    from = "child"
+}
diff --git a/terraform/test-fixtures/plan-module-provider-defaults-var/main.tf b/terraform/test-fixtures/plan-module-provider-defaults-var/main.tf
new file mode 100644
index 000000000000..83b2411543c0
--- /dev/null
+++ b/terraform/test-fixtures/plan-module-provider-defaults-var/main.tf
@@ -0,0 +1,7 @@
+module "child" {
+    source = "./child"
+}
+
+provider "aws" {
+    from = "${var.foo}"
+}